Process for the production of coreelectrodes



mama July 19,1938 2,124,255

UNITED STATES PATENT OFFICE PROCESS FOR THE PRODUCTION OF GORE- ELECTRODES Frans Leitn'er, Kapfenberg, Austria No Drawing. Application May 23, 1935, Serial No. 22,917. In Germany May 23, 1934 2 Claims. (Cl. Ill-8) Core-electrodes having alkaline-earth metals pipe. The latter pipe, preferably closed at one as calcium, magnesium, or the carbides thereof, end, can be made of mild iron or alloy steel of aluminium or alkaline metals are known. such a composition that its alloying elements have The use of the aforesaid materials for core a beneficial influence upon the deposited metal.

wires is limited, however, and requires special An enrichment of alloying metals in the in- 5 working processes. If the core materials have a terior of the wire, as a consequence of the use of low melting point, difliculties arise insofar as the an alloyed steel pipe has particular advantages. core partly or entirely melts when the ingots or The requirements for a good weld obtained by billets are heated to a rolling temperature. Thus, this process are better than if the metals were 1 if a wire is produced with such materials an irequally distributed throughout the whole section. 10 regular form of the core and very often a non- The explanation is that during the welding the uniform mixture of the different components reatmosphere affects the outer parts of the drops suits. These irregularities cause an irregular of metal first so that the inner parts containing melting process and give poor qualities to the dethe alloyin elements remain unflflectedposited metal. The hollow ingots thus made are afterwards 15 Generally, many core materials alter their filled with the core materials and worked down to chemical composition at the rolling temperature wire. under the influence of heat or of the furnace An h r Way f ryin out the Process 1- gases or of the atmosphere. In this way the irs sts n ins rt th pipe. l s d at one nd. into regularities of the welding process and poor the mould filled with the liquid steel and inserting 20 qualities of the weld are increased, the core materials in the hollow ingot afterwards.

The present invention consists in selecting only It i furthermore, p l to P l f ry such materials which melt at a higher temperar con t e additions or an e pty steel ture than about 900 C. and which are chemically P p 8 fi y P p filled with he add ti ns stable at this temperature. The selection must into th P p before casting and n r l n he 25 be done in such a way that the arc-stabilizinggots. The refractory filling may, if desired, be effect and oth r requirements for welding are provided with metallic inserts to make it stronger. present. The following additional materials are y the 1 named P 8 ental effect proposed: alkaline earth and/or alkaline comthe hlghfiempemture is hardly to be avoided pounds containing oxygen and lk i earth for which reason, the core materials must be 30 and/or alkaline compounds free of oxygen, more resistant to heat than if they are filled Furthermore, metal oxides or compounds of metal after casting. oxides and metal alloys in combination with what I c1mm 1S! themselves or with the aforementioned materials A P e Production of core electrodes may be used. The choice should be made in such p in p a n a p pe in a d aini 35 a way that the above named physical and chemiliquid Steel and then fillin! the p p with a recal requirements are fulfilled. iractory material having a melting point above To avoid any detrimental effects of the melt- 0 C- in temperature upon th c r at i l it, i 2. A process as claimed in claim 1 wherein as a rule, preferred to fill the ingots after casting. the refractory material comprises at least one ma- The process may, however, be performed in difterial selected from a g oup sting of alkaline ferent ways and some of these are now described. earth and alkaline compounds containing oxygen The ingot or billet to be rolled into wire can be and alkaline earth and alkaline compounds free made hollow and then provided with additions from oxygen and metal oxides and metal oxide which are stable at high temperatures. The hole compounds.

of the ingot or billet can be made by boring. by FRANZ IEI'I' piercing or by casting the steel around an empty 

